front-end developer, audio & video engineer

If you need to play back video clips in a presentation with the highest possible confidence nothing will go wrong, use PlaybackPro.

If you can't use PlaybackPro, use Keynote.

If your only option, however, is PowerPoint running on a Windows laptop (as it was for me this week), most combinations of file formats and codecs won't work. This was the ffmpeg command that worked best: